1. Technical Field
The present invention relates to information processing, and in particular relates to information processing for the purpose of implementing error control such as error detection and error correction.
2. Description of the Related Art
When digital information is transferred, recorded or reproduced, in some instances errors can occur in portions of the digital information, due for example to the effects of alpha rays or other cosmic rays, to a defect on the transmission path, and so on. There are known technologies that employ error detecting code or error correction code in order to detect such errors and correct any detected errors. There is no fundamental difference between an error detecting code and an error correction code, and they may be referred to collectively as error control codes. Similarly, error detection and error correction may be referred to collectively as error control.
In transferring or recording digital information using error control codes, for example, m-bit error control information (redundant bits) is appended to k-bit digital information (information bits) to generate a (k+m)-bit codeword, and this codeword is then transferred. At the transfer destination of the codeword, error detection or error correction is performed using the redundant bits contained in the codeword. The process of generating the codeword is termed “encoding”; the process of error detection or error correction based on the codeword is termed “decoding.”
Various codes for the purpose of error control are known. For example, JP-H5-197580A discloses an error control code capable of correcting one-bit errors, as well as detecting two-bit errors.
With a view to further improving reliability during transfer or recording of digital information, it is preferable to employ error control codes having high error correction/error detection capability. However, where codes with high error correction/error detection capability are used, the bit length of the redundant bits tends to be longer, and efficiency of transfer of information tends to decline.